The OR-13-BN is a Buna-N O-ring used for sealing strain relief fittings. It is specifically designed for PG 13 and PG 13.5 threads, featuring an inner diameter of 0.67 inches (17 mm) and a height of 0.07 inches (1.8 mm). This O-ring is the recommended solution for straight strain relief fittings with a molded groove. It is required when mounting these fittings to achieve a NEMA 4x or 6 (IP68 or IP69K) submersible rating.